Dies for forming reference surfaces on articles circular in cross-sections



March 10, 1953 c. HERZOG 2,630,727

DIES FOR FORMING REFERENCE SURFACES 0N ARTICLES CIRCULAR INCROSS-SECTIONS Filed April 5, 1949 INVENTOR C .HERZOG A T TORNE YPatented Mar. 10, 1953 DIES FOR FORMING REFERENCE SURFACES ON ARTICLESCIRCULAR IN CROSS-SEC- TIONS Carl Herzog, Belleville, N. J assignor toWestern Electric Company, Incorporated, New York, N. Y., a corporationof New York Application April 5, 1949, Serial No. 85,612

This invention relates to dies for forming rererence surfaces onarticles circular in cross-section, and more particularly for formingcontacts whereby they may be mounted accurately in electrical units.

Certain electrical units employed in the communication arts includecontacts which must be accurately positioned with respect to each otherand with respect to the centerline of the unit in which they aredisposed so that the unit may function efficiently. One form of suchunits is a mercury switch including pairs of contacts which are to beelectrically engaged by a switch element requiring accurate positioningof the contacts relative to each other in their respective pairs andrelative to the switch member so that the switch may function properly.The contacts are usually formed of certain types of wire circular incross-section having smaller portions of precious metal welded thereonto be engaged by the switch member during operation of the switch. Thepresence of the portion of precious metal on each contact adds to thediificulty of mounting the contacts in the electrical unit so that theseportions of precious metal may be positioned for engagement with theswitch element.

An object of the present invention is to provide a die which is simplein structure, readily actuable and highly efficient in forming referencesurfaces on an article circular in cross-section.

With this and other objects in view, the invention comprises a die forformng reference surfaces on an article circular in cross-section, thedie including a fixed die member having a cavity to receive the articleand a second die member having a cavity to cooperate with the cavity ofthe fixed die member to form reference surfaces on the article which areparallel with the centerline of the article.

More specifically the die members are so formed that two sets ofreference surfaces are formed on the article, the first set lying in agiven plane with the centerline of the article, while the other setincludes parallel reference surfaces spaced equal distances from thecenterline of the article and at right angles to their respective firstreference surfaces. The second die member is also formed to cause theportion of precious metal welded to the article or contact to be formedso that its outermost surface will be a given distance from the planeincluding the first reference surfaces and the centerline of thearticle. A stop member, in the form of a rod, a-djustably carried by aholder and extending into the cavity of the fixed die member varied dis-1 Claim. (Cl. 78-451) tances depending upon the desired length of thereference surfaces may be secured at any selected position in a holdertherefor, secured to the fixed die member. Other objects and advantageswill be apparent from the following detailed description when consideredin conjunction with the accompanying drawing, wherein Fig. 1 is a sideelevational view of the die, portions thereof being broken away;

Fig. 2 is a vertical sectional view taken substantially along the line2-2 of Fig. 1;

Fig. 3 is a fragmentary isometric view of a portion of an article orcontact to be formed by the die; i

Fig. 4 is a top plan view of the article after it has been formed by thedie; and

Fig. 5 is a sectional view taken along the line 55 of Fig. 4.

Referring now to the drawing, th die includes a fixed die member H!having a cavity I I extending the full length of the die member. The diemember ID is securedto the side or aligning members I2 by machine screwsl 4, these members being mounted with the die member upon a mountingplate I 5 by suitable means (not shown). The mounting plate 15 issecured to the bed It of a conventional press having a recip-rocable ram11 operable in single cycles by suitable means (not shown). A second diemember 20, is supported by the ram I! for movement relative to itscompanion die member i0 between the side or aligning members 12. Acavity 2! is formed in the under surface of the die member 20 for thefull length thereof, cooperating with the cavity H to form the articleshown in Fig. 3 into the contour illustrated in Figs. 4 and 5. A stop 23in the form of a rod extends through an aperture 24 in a holder 25mounted on the back surfaces of the members 1'2 whereby the rod or stop'23 may be located at any desired position within the cavity III andheld in place by a set screw 26' to limit the distance an article 26extends into the die cavity.

In the present embodiment of the invention, the article 26 is a metalstructure in the form of a contact wire, circular in cross-section andhaving a portion 21 of precious metal welded to the periphery thereof, agiven distance from the leading end 2-8 of the article.

During operation of the die, the ram l1 with the die member 20 isreciprocated through operating cycles, each time an article 26 is placedin the die cavity H. As previously stated, the distance the article orcontact extends into the 8* die cavity I I is determined by the stop 23.When the die is closed on the article 20 with the portion 21 disposed onthe uppermost portion of the article in the die cavity ll, two sets ofreference surfaces 30 and 3| are formed on the article. The first; setof reference surfaces 3B Wi11 be in a givenJplane-with thecenterlinepfthe article whereby the utilization of a holder for the mounting of thearticle or contact in an electrical unit,

and it will be known that a surface of the holder contacting thereference surface 30 will lie in a plane with the centerline of thearticle. The reference surfaces 3| will be formed at right angles totheir respective reference surfaces 30 equal distances from thecenterline of thearticle. With the two sets of reference surfaces 30 and3|, it is possible to accurately locate thecontact.

or article within a unit of which it. is to be a part. It will also benoted that the cavity 2|: is formed whereby the. portion 21 of preciousmetal will be formed. simultaneously with the forming. of; the-referencesurfaces 30 and 3.! to

'causerthe outermostsurface 33' thereof to be located a known distancefrom the plane of the reference surface 30.

It is to be understood that the above described arrangements are simplyillustrative of theapplication of the principles of the invention.Numerous-other arrangements may be readily devised by those skilled inthe. art which will .embodythe principles of theinvention and fallplaced. in: the cavity, asecond die member having a flat face parallelto the flat face of the first die member and also having an invertedU-shaped longitudinal cavity parallel to and narrower than the cavity ofthe first die member, the sides of the U-shaped cavity beingperpendicular andspaced. equal distances from the center of the circularconductorwhen in the die members to shear and forge the sides of saidcylindrical conductor to form flat side reference surfaces substantiallyin the plane of the meeting point of the die members and through thecenterof said conductor, said inverted u-shaped cavity having a depth toclear the exposed portionof said'conductor located between the portionsthat are sheared and forged and to clear the lower sides of saidcontact, the bottom of said. U-shapedcavity having a contoured surfacefor engaging and working the top surface of the precious metal contact,and means to cause relative movement of the die members to engage theconductor and the precious metal thereonto form an electrical contactunit having two spaced right angled pairs of reference surfaces and anouter reference surface on the precious metal, all of said surfacesbeing at predetermined fixed distances from the said center of theconductor.

CARL HERZOG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 445,001 Bush Jan. 20; 1891446,281 Bush Feb. 10,.1891 446,768 Bush Feb. 17, 1891 1,440,802 SmithJan. 2', 1923 1,440,843 Smith Jan. 2, 1923 1,466,844v McGuckin Sept. 4,1923 1,899,288 Metcalf .Feb. 28, 1933 2,433,152 Patnaude Dec. 23, 1947

